[PATCH] sysdeps/unix/sysv/linux/microblaze/pselect32.c: add missing implementation when !__ASSUME_TIME64_SYSCALLS

[Thomas Petazzoni]

In commit a92f4e6299fe0e3cb6f77e79de00817aece501ce ("linux: Add time64
pselect support"), a Microblaze specific implementation of
__pselect32() was added to cover the case of kernels < 3.15 which lack
the pselect6 system call.

This new file sysdeps/unix/sysv/linux/microblaze/pselect32.c takes
precedence over the default implementation
sysdeps/unix/sysv/linux/pselect32.c.

However sysdeps/unix/sysv/linux/pselect32.c provides an implementation
of __pselect32() which is needed when __ASSUME_TIME64_SYSCALLS is not
defined. On Microblaze, which is a 32-bit architecture,
__ASSUME_TIME64_SYSCALLS is only true for kernels >= 5.1.

Due to sysdeps/unix/sysv/linux/microblaze/pselect32.c taking
precedence over sysdeps/unix/sysv/linux/pselect32.c, it means that
when we are with a kernel >= 3.15 but < 5.1, we need a __pselect32()
implementation, but sysdeps/unix/sysv/linux/microblaze/pselect32.c
doesn't provide it, and sysdeps/unix/sysv/linux/pselect32.c which
would provide it is not compiled in.

This causes the following build failure on Microblaze with for example
Linux kernel headers 4.9:

/home/thomas/buildroot/buildroot/output/host/lib/gcc/microblazeel-buildroot-linux-gnu/10.3.0/../../../../microblazeel-buildroot-linux-gnu/bin/ld: /home/thomas/buildroot/buildroot/output/build/glibc-2.34-9-g9acab0bba6a5a57323b1f94bf95b21618a9e5aa4/build/libc_pic.os: in function `__pselect64':
(.text+0x120b44): undefined reference to `__pselect32'
collect2: error: ld returned 1 exit status

To fix this, we take a crude approach: replicate in
sysdeps/unix/sysv/linux/microblaze/pselect32.c the
!__ASSUME_TIME64_SYSCALLS implementation that is already in
sysdeps/unix/sysv/linux/pselect32.c.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 .../unix/sysv/linux/microblaze/pselect32.c    | 22 +++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/microblaze/pselect32.c b/sysdeps/unix/sysv/linux/microblaze/pselect32.c
index 70b7b52a48..6b6b3e8a2e 100644
--- a/sysdeps/unix/sysv/linux/microblaze/pselect32.c
+++ b/sysdeps/unix/sysv/linux/microblaze/pselect32.c
@@ -22,7 +22,25 @@
 #include <sys/poll.h>
 #include <sysdep-cancel.h>
 
-#ifndef __ASSUME_PSELECT
+#if !defined(__ASSUME_TIME64_SYSCALLS)
+int
+__pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
+	     fd_set *exceptfds, const struct __timespec64 *timeout,
+	     const sigset_t *sigmask)
+{
+  struct timespec ts32, *pts32 = NULL;
+  if (timeout != NULL)
+    {
+      ts32 = valid_timespec64_to_timespec (*timeout);
+      pts32 = &ts32;
+    }
+
+  return SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds,
+			 pts32,
+			 ((__syscall_ulong_t[]){ (uintptr_t) sigmask,
+						 __NSIG_BYTES }));
+}
+#elif !defined(__ASSUME_PSELECT)
 int
 __pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
 	     fd_set *exceptfds, const struct __timespec64 *timeout,
@@ -57,4 +75,4 @@ __pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
 
   return ret;
 }
-#endif /* __ASSUME_PSELECT  */
+#endif
-- 
2.31.1